The disclosure relates generally to the drive of a sliding door or swinging-sliding door of a rail vehicle, and more specifically it relates to a drive having a guide rail fixed with respect to the rail vehicle, and on which guide rail a carriage is longitudinally displaceably and optionally rotatably arranged, which carriage carries a door leaf, and having a spindle drive whose spindle extends parallel to the guide rail and whose spindle nut is fixedly connected with the carriage in the direction of the axis of the spindle.
A similar drive is known from the applicant's European Patent Document EP 0 461 104 A. However in this case, instead of providing a spindle drive, a linear drive is provided whose driving device can move only along a straight line extending parallel to the guide rail. The transmission of force from the driving device to the carriage takes place in that the driving device is arranged between two wings of the carriage which extend in a normal manner with respect to the guide rail. The wings are so large that, during the rotating movement of the carriage, the driving device does not leave this area. This solution has been successful in general. However, since linear drives are expensive as well as maintenance-intensive particularly in comparison to spindle drives, a solution is needed with respect to a spindle drive in which the rotating position of the spindle nut is defined by the output. The known solution is not suitable for this purpose.
In a construction which has been known for some time and has been successful, the door leaf hangs on a carriage which itself is displaceable along a circular guide rail fixed to the body. The carriage can also be swiveled about the guide rail, and the door leaf is also linked to the carriage and is swivellable parallel to the axis of the guide rail, whereby the tilt-out movement of the door leaf is ensured. The drive includes a driving spindle rotatable about itself and fixed to the body and a spindle nut running on the spindle. The connection between the spindle nut and the carriage includes a connecting rod which can be swiveled on the spindle nut as well as on the carriage in each case about an axis parallel to the axis of the guide rail.
This construction has essentially been successful and, as mentioned above, has been used for some time but still has certain disadvantages: The connecting rod, by which the moving forces for the door leaf are transmitted in the direction of the axis of the guide rail, is stressed with respect to bending and shear by these considerable forces. These forces have to be transmitted by the two hinge joints, which requires that they be constructed in a correspondingly massive and therefore heavy and expensive manner. As a result of the relatively large distance of the connecting rod or its hinge joints with respect to the axis of the guide rail, on the one side, and with respect to the axis of the spindle, on the other side, the carriage as well as the spindle nut are stressed during the operation on their seats with respect to tilting. In the case of the carriage, this results in an increased edge pressure and, in the case of the spindle nut, results in a one-sided loading of the thread. In addition to all of the above, sufficient space has to be left for the sliding-past of the connecting rod over the entire moving path of the carriage.
Also in the case of pure sliding doors having the initially defined basic construction, it is necessary, for the compensation of tolerances, wear phenomena, different thermal expansions and the like, to use a construction having a connecting rod, which causes the same problems as in the case of swinging-sliding doors.
It is an object of the invention to avoid the above-mentioned disadvantages and provide a construction which requires less space, has a dynamically and statically more favorable flow of force and is also cost-effective in its production. According to the present disclosure, these objects are achieved in that the connection between the spindle nut and the carriage takes place by means of a sliding hinge joint which permits a relative rotating movement as well as a displacing movement in the joint area.
In this manner, it is achieved that the connecting rod can be completely eliminated and that, instead of the two hinge joints, a single hinge joint combined with a displacing seat is provided. The hinge joint is situated essentially in the area of the direct connection between the axes of the guide rail and the spindle. In this manner, the above-mentioned disadvantages of the force transmission by the unfavorable eccentric arrangement are completely avoided, and the displacing seat may be constructed by a claw-type construction of the radial projection on a relative large surface, so that the surface pressure can be minimized.
Furthermore, this construction permits the axial adjusting of the door leaf by inserting or removing shims and thus eliminating the previously necessary adjustment by means of expensive threaded bolts.
These and other aspects of the present disclosure will become apparent from the following detailed description of the disclosure, when considered in conjunction with accompanying drawings.